1. Field of the Invention
This invention relates generally to rolling mill oil film bearings, and is concerned in particular with an improvement in the hydraulically actuated devices designed to urge the bearings onto and off of the roll necks.
2. Description of the Prior Art
In the conventional rolling mill oil film bearing, an annular hydraulically actuated piston/cylinder unit is employed to urge the bearing onto and off of the roll neck. The piston/cylinder unit is axially mounted on a cylindrical section of the roll neck and is confined at the inboard end by a shoulder on the roll neck and at the outboard end by a split retaining ring seated in a groove in the roll neck. The split retaining ring has a central bracket to which locking arms are connected by hinge pins. The locking arms are pivotally adjustable about the hinge pins between open positions removed from the neck groove, and closed positions seated in the groove.
Experience has shown that as the roll rotates during operation of the mill, a problem sometimes occurs due to failure of the hinge pins or the areas of the lock arms surrounding the hinge pins. When this occurs, centrifugal force causes the lock arms to be thrown outwardly, resulting in damage to the bearing and a disruption of the rolling process.
Efforts to overcome this problem have included the installation of separate safety cages designed to retain the lock arms in the event of failure of the hinge connections, and the introduction of larger clearances between the hinge pins and lock arms in an attempt at eliminating troublesome interferences. The safety cages disadvantageously add to the complexity and cost of the bearings, whereas increased clearances tend to make installation and removal of the retaining ring somewhat clumsy.
The object of the present invention is to provide an improved means for reliably retaining the lock arms in their closed positions.